Three tested disease groups comprising of 31 early onset Alzheimer’s disease patients, 68 late onset Alzheimer’s disease patients, and 91 Graves’ disease patients (Table 1) were used in this study to assess DNA methylation profile and predictive performance of five selected age-related CpG sites (ELOVL2 c7, C1orf132 c1, FHL2 c2, TRIM59 c7, KLF14 c1) in these disease groups. This evidence concerns the gene KLF14 and early-onset autosomal dominant Alzheimer disease.